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Biomedical subjects

L Sherwood

Publications and source records attributed to L Sherwood.

6 recordsLinked to original sources
PubMed2001

Importance of precision in bone density measurements.

Bone densitometry, regardless of the specific technique, is not perfectly reproducible even when consistently performed in exact accordance with the manufacturer's recommendations. Precision must be quantified at each densitometry facility in precision studies of the various skeletal sites used for monitoring. The precision, as the root-mean-square standard deviation or root-mean-square coefficient of variation, is then used to determine the change in bone density that constitutes the least significant change and the minimum interval between follow-up measurements. Until precision studies are performed, the least significant change cannot be determined for any level of statistical confidence, making the interpretation of serial studies impossible.

Absorptiometry, Photon↗
PubMed1998

Design of NORA, the National Osteoporosis Risk Assessment Program: a longitudinal US registry of postmenopausal women.

NORA is an observational registry of postmenopausal US women with periodic collection of event and treatment data that will create a database including several hundred thousand subjects. It will utilize peripheral and central measurements of bone density and relate these to other risk factors, treatment patterns, and the natural history of osteoporosis. Initiated in the fall of 1997, the registry will be open to women throughout the United States who agree to complete baseline and on-going surveys. The database created by NORA will provide a resource that is unmatched in size and scope in the medical field and will allow for future research in a number of areas including patient outcomes, types of follow-up employed in clinical practice, diagnostic cost modelling, and osteoporosis therapy use (type, patient compliance, persistence and satisfaction). In addition, upon approval by the Steering Committee, women enrolled in the registry may be randomly selected to receive additional educational materials or questionnaires on a variety of topics of interest to specific researchers.

Bone Density↗
PubMed1986

A hydrostatic weighing method using total lung capacity and a small tank.

The purpose of this study was to establish the validity and reliability of a hydrostatic weighing method using total lung capacity (measuring vital capacity with a respirometer at the time of weighing) the prone position, and a small oblong tank. The validity of the method was established by comparing the TLC prone (tank) method against three hydrostatic weighing methods administered in a pool. The three methods included residual volume seated, TLC seated and TLC prone. Eighty male and female subjects were underwater weighed using each of the four methods. Validity coefficients for per cent body fat between the TLC prone (tank) method and the RV seated (pool), TLC seated (pool) and TLC prone (pool) methods were .98, .99 and .99, respectively. A randomised complete block ANOVA found significant differences between the RV seated (pool) method and each of the three TLC methods with respect to both body density and per cent body fat. The differences were negligible with respect to HW error. Reliability of the TLC prone (tank) method was established by weighing twenty subjects three different times with ten-minute time intervals between testing. Multiple correlations yielded reliability coefficients for body density and per cent body fat values of .99 and .99, respectively. It was concluded that the TLC prone (tank) method is valid, reliable and a favourable method of hydrostatic weighing.

Adolescent↗